38 FLORIDA GEOLOGICAL SURVEY—THIRD ANNUAL REPORT. 
have as suggested by Matson*, washed into this deposit from some 
pre-existing formation. This can not apply, however, to the oc¬ 
casional complete skeletons that are found in these deposits. It 
is probable that the formation accumulated in comparatively shallow 
water. That the water was not deep is evident from the irregu¬ 
larity of the stratification and from the occasional cross bedding. 
Also that the place of accumulation was not far removed from 
land is indicated by the comparatively coarse material and by the 
presence of numerous bones of land animals. 
CHANGE OF CONDITIONS DURING DEPOSITION. 
The land pebble phosphate formation, as previously stated, is 
not of uniform character throughout, indicating that the conditions 
varied from time to time during the accumulation of the material. 
The earliest phase of the formation observed consists of clear 
quartz grains and very small black pebble phosphate forming 
a stratum one to four feet in thickness. This material occurs 
only locally and is non-workable, the phosphate pebble being too 
small to separate from the sand. This phase of the formation 
may be observed in the pit of the Pierce Phosphate Company, six 
miles south of Mulberry. The formation divides itself into the 
workable phosphate stratum and the indurated sands forming a 
part of the overburden previously described. Stratigraphically 
the most pronounced break in the formation is that which occurs 
within the phosphate stratum itself, particularly in the northern 
part of the phosphate field, where the pebble phosphate con¬ 
glomerate rests upon the underlying clayey phosphate matrix. 
This conglomerate grades above very gradually into the overlying 
gray sands. A change in condition in deposition is clearly in¬ 
dicated. This change probably indicates elevation of the land to 
the north. Following this elevation there was brought in first the 
coarse phosphatic material accompanied by the flint and corals, 
and later the sands which make up the upper member of the for¬ 
mation. 
STATE AND GOVERNMENT LANDS IN THE PHOSPHATE SECTION. 
Both the State and the National Governments still own lands 
in the phosphate sections of the State. All State lands have been 
withdrawn from sale by order of the Internal Improvement Board 
until properly classified. 
The President, by executive order has withdrawn during the 
year 27,400 acres of Government land in the phosphate section of 
Florida. 
*Florida Geol. Survey, Second Annual Report, p. 140, 1909. 
